Effect of dopamine on prostaglandin E2 content in gastric mucosa.
The effects of dopamine (DA) on the prostaglandin (PG) E2 content of rat gastric mucosa was investigated. There was a 17.5% increase in gastric mucosal blood flow (BF) after administration of DA (5 micrograms/kg/min iv). After pretreatment with fusaric acid (FA), an antagonist of dopamine beta hydroxylase, DA increased BF by 27.8%. The PGE2 content in DA and DA + FA groups increased at rates of 45.8% and 42.4%, respectively. The PGE2 content in gastric mucosa after incubation following Basso's method, increased in the DA, DA + FA and noradrenaline (NA) groups to 3.32 +/- 0.40 micrograms/g, 3.30 +/- 0.39 micrograms/g and 3.37 +/- 0.42 micrograms/g respectively. It is concluded that there are no differences in PGE2 content among the DA, DA + FA and NA groups. The mechanism by which PGE2 content increases after administration of DA is the direct action of DA and/or increasing BF. It is suspected that DA directly affects PGE2 synthesis, however the possibility that DA is metabolized to NA, which secondarily results in increased PGE2 synthesis, cannot be excluded.
Nagahata
Y
Y
First Department of Surgery, Kobe University School of Medicine, Japan.
Urakawa
T
T
Saitoh
Y
Y
D000818:Animals; D015232:Dinoprostone / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology*; D005669:Fusaric Acid / Q000494:pharmacology; D005753:Gastric Mucosa / Q000098:blood supply / Q000187:drug effects*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D013268:Stimulation, Chemical
D005669:Fusaric Acid; D015232:Dinoprostone; D004298:Dopamine